The transport of Fe(III)-pyochelin by Pseudomonas aeruginosa has been investigated. The receptor for Fe(III)-pyochelin has been determined to be a about 75 kDa outer membrane protein. Mutants lacking this outer membrane protein have an absolute defect in the transport of Fe(III)-pyochelin. This finding refutes the previous designation of a 14 kDa outer membrane protein as the receptor for Fe(III)-pyochelin. Work on pyochelin analogues has resulted in the discovery of a novel artificial siderophore and iron transport system in P. aeruginosa. Although this artificial siderophore, trivially designated HTC, has structural similarities to pyochelin, its transport is independent of the Fe(III)-pyochelin receptor.